You are not planning to build anything. So why read about floor area ratios? Because these rules shaped the building you are about to live in, and they also decide what can rise on the empty land next door.
Three rules, three questions
- FAR or FSI: how much floor area can be built in total?
- Ground coverage: how much of the land can the building sit on?
- Setbacks: how far must the building stay from each edge of the land?
FAR, in one example
Floor area ratio is the total floor area allowed, divided by the land area. If a 10,000 sq ft piece of land has a FAR of 1.75, the total floor area across all floors can be 17,500 sq ft. That could be a few large floors or many small ones. FAR does not say which; the other two rules help decide.
FSI, or floor space index, is the same idea under another name. Where a document uses either term, read its own definition. What counts towards the total, such as balconies or parking, is not the same everywhere.
Ground coverage
Coverage is the share of the land the building's footprint can take up. Put the same FAR with a tight coverage limit and you get a taller, slimmer building with open ground around it. Loosen the coverage and the building spreads out and stays low. Open ground for children, trees and air comes from coverage and setbacks, not from FAR alone.
Setbacks
A setback is the minimum gap between a building and its boundary, set separately for front, back and sides. The gap usually grows with plot size, road width and building height. Setbacks do four jobs:
- Let in light and air for you and your neighbours.
- Leave room for a fire engine to reach the building.
- Make space for drains, cables and rainwater pipes.
- Keep land free where the city plans to widen a road.
Where these numbers come from
There is no single national FAR. In Karnataka, the zoning rules come from the development plan for the area, made under the Karnataka Town and Country Planning Act, 1961, read with the building bye-laws of the authority that approves plans. That authority depends on where the land sits. Because these figures change when plans and bye-laws are revised, we do not print them here. Read them from the rules in force for the zone, or from the sanctioned plan of a specific project.
Why a first-home buyer should care
The approval already tested them. When a project gets its plan sanctioned, the authority checks it against FAR, coverage and setbacks for that zone. In a RERA-registered project, section 19(1) of the Real Estate (Regulation and Development) Act, 2016 lets you get information on the sanctioned plans, layout plans and specifications. Ask for them and look at the setbacks drawn on the plan.
Density is something you will live with. Lift waits, parking, noise and how crowded the play area feels all follow from how many homes share the land. A simple way to compare projects is homes per acre. For example, our project The Shalott Marque has 54 homes on 0.75 acres, which works out to 72 homes per acre. You can do the same sum for any project with two published numbers. Read more about the project on The Shalott Marque page.
The plot next door is not a promise. An empty plot beside your building is governed by the same rules for its own zone and road width. A view sold as permanent is only as permanent as the zoning allows. Asking what the neighbouring land is zoned for tells you more than any assurance.
Quick reference
| Rule | What it controls | Where to read it |
|---|---|---|
| FAR / FSI | Total floor area on all floors | Zoning rules of the plan in force |
| Ground coverage | Footprint on the land | Zoning rules and building bye-laws |
| Setbacks | Gap from each boundary | Building bye-laws |
| Height | Floors and total height | Bye-laws, plus fire and airport clearances where needed |
You do not need to become a planner. You only need to ask for the sanctioned plan, look at the gaps around the building, and work out homes per acre. Those three habits tell you a lot about daily life in a building.
A worked example: from FAR to number of homes
Illustrative figures, not the rules of any particular zone. Take one acre of land, which is 43,560 sq ft. Suppose the permitted FAR is 2.0. The total floor area allowed is 43,560 × 2.0 = 87,120 sq ft. Not all of that becomes homes. Corridors, lift lobbies, staircases and other common areas take a share. If one-fifth goes to these, about 69,700 sq ft is left for flats.
Now divide by the size of flat. At an average built area of 1,000 sq ft, that is about 70 homes on the acre. At 700 sq ft, nearer 100. Same land, same FAR, a very different community. This is why the number of homes per acre tells you more than the FAR alone.
Step by step: reading the sanctioned plan
- Ask the builder for the sanctioned plan and its approval reference, which section 19(1) of RERA entitles you to.
- Find the site plan, the drawing that shows the building inside the boundary.
- Read the setback figures written on each side. Note which side faces the road.
- Look for the area statement, a table that gives the plot area, permitted and achieved FAR, and ground coverage.
- Check the number of floors and units against what the brochure says.
- Compare the plan uploaded on the RERA website with the one you were given.
Common mistakes
- Treating a big FAR as a good thing. More floor area on the same land usually means more people sharing it.
- Assuming the open space in a render is all yours. Some of it may be the setback, which must stay clear for fire access.
- Not asking about future phases. If the land has more FAR left to use, another tower may come later. Ask whether the sanctioned plan is the full plan.